Re: Does computer know what octane you're running?
[Re: RodStRace]
#1441216
05/24/13 07:35 PM
05/24/13 07:35 PM
|
Joined: Sep 2007
Posts: 14,889
up yours
Supercuda
About to go away
|
About to go away
Joined: Sep 2007
Posts: 14,889
up yours
|
Today's gas goes stale quicker than it did. Might have been a tankful of stale gas they were getting rid of with a story.
You could try another tankful of premium from another source to see.
They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
|
|
|
Re: Does computer know what octane you're running?
[Re: Supercuda]
#1441217
05/24/13 10:32 PM
05/24/13 10:32 PM
|
Joined: Jan 2003
Posts: 20,788
A collage of whims
topside
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 20,788
A collage of whims
|
My '97 Mustang GT runs on anything, but its computer adjusts timing for detonation. Seems a bit perkier on 92 than 87, but never had a problem starting it.
Last edited by topside; 05/25/13 10:40 AM.
|
|
|
Re: Does computer know what octane you're running?
[Re: topside]
#1441218
05/25/13 02:24 AM
05/25/13 02:24 AM
|
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
|
Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
|
I'm not aware of sensors that read octane, but there must be SOMETHING that the computer reads to know the difference in E10 and E85 to automatically adjust the tune. Supposedly "perfect stoich" of ethanol is not 14.7:1 like regular gas so the computer can't read JUST the O2 sensors, can it?
And not all cars have knock sensors...
I'd guess it was just a tank of bad gas. Want to test your theory? Get premium gas from another station... Chances of getting 2 tanks of bad gas from 2 different stores "back to back" is very slim.
**Photobucket sucks**
|
|
|
Re: Does computer know what octane you're running?
[Re: 70Cuda383]
#1441220
05/25/13 11:19 AM
05/25/13 11:19 AM
|
Joined: Sep 2005
Posts: 12,481
Chino Valley
RodStRace
I Live Here
|
I Live Here
Joined: Sep 2005
Posts: 12,481
Chino Valley
|
Quote:
I'm not aware of sensors that read octane, but there must be SOMETHING that the computer reads to know the difference in E10 and E85 to automatically adjust the tune. Supposedly "perfect stoich" of ethanol is not 14.7:1 like regular gas so the computer can't read JUST the O2 sensors, can it?
And not all cars have knock sensors...
I'd guess it was just a tank of bad gas. Want to test your theory? Get premium gas from another station... Chances of getting 2 tanks of bad gas from 2 different stores "back to back" is very slim.
Tom,
Fuel sensors are on every flex fuel vehicle.
There are even DTCs for them.
P0169, P0176, P0177, P0178, P0179.
Also, since as you say the A/F ratio is different for gas, alky and any blend, when in feedback (operating temp, not WOT or decel, O2 providing results), it can 'see' that it's too rich or lean and compensate, although that's not 100% and not all the time. O2 feedback is better used to trim or adjust the programmed ratio, not make broad changes. Gasoline is 14.7:1, alky is 5.0-6.0:1.
These are by weight too!
More at http://www.smokemup.com/tech/fuels.php
Not all cars have knock sensors, but GM LOVES 'em and I guessed that any Buick Enclave (2008-present)
http://www.edmunds.com/buick/enclave/
Is going to have 'em.
Ford loves to 'test' theirs by purposely overadvancing the timing on acceleration and using the knock sensors to pull timing out.
and I agree on the bad load...
|
|
|
|
|
